After more than a month of unseasonal mildness, winter seemed to come to the Yare in one great rush. As I looked upstream along the valley, the cloud was towering into the sky in an advancing black horde. As a prelude to the downpour, the vegetation went into a gale-lashed frenzy as if it were desperate to escape the inevitable onslaught.

There were three basic notes in the music of the south-west wind. The quietest, a sort of brushed hiss, came from the grass. Soft and insistent, it kept to ankle level and I had to strain to pick it out from the wider sound-scape. The second and most pleasing contribution rose from the long bed of Phragmites reeds, which were pressed over by the wind to an angle of about 60 degrees from the ground. The flat blade-like leaves tugged constantly at their stem, and seemed to be reaching out to the north-east in a hopeless plea for mercy. Yet there was some comfort in the song of these reedbeds, which rustled soothingly like a generous flow of meal on to a stone floor.

There was, however, no consolation in the noise above me. The trees, a line of thick-trunked poplars, had been stripped of leaves; and the wind worked the bare twigs, the branches and even the trunks, sounding a dark booming base, like the relentless impact of water upon shattered rock.

Then came the first rain and instantly the rich green tones in the far landscape withered to shades of grey or black. Finally, I too was engulfed. The scribbled lines in my notebook bled one into the other, and the words that I offer you now melted slowly in the winter rain.

· Mark Cocker's book A Tiger in the Sand: Selected Writings on Nature (Jonathan Cape, £10) is published this week